氮素形态及pH值交互作用对甜菜产量和含糖率的影响

EFFECTS OF NITROGEN FORMS AND PH INTERACTION ON ROOT YIELD AND SUGAR CONTENT IN SUGAR BEET

采用3因素5水平二次旋转回归设计,以Hoagland营养液为基础,以pH、硝态氮(NO3--N)和铵态氮(NH4+-N)为处理因子进行水培试验,建立了多因子复合处理对甜菜(Beta vulgaris L.)品种甜研7号块根产量和含糖率影响的回归模型,并分析了各因子的主效应和互作效应。结果表明:在本试验条件下,影响甜菜块根产量和含糖率的单因子主效应大小均为NO3--N>pH>NH4+-N;pH在6.2～7.0范围内,对产量和含糖率的影响表现为正效应,在7.0～7.8之间,表现为负效应;NO3--N(0～16mmol.L-1)对产量表现正效应,而对含糖率则为负效应;在0～8.0mmol.L-1范围内,NH4+-N对产量影响为正效应,在8.0～16.0mmol.L-1之间为负效应,0～16mmol.L-1对含糖率影响为负效应。NO3--N与NH4+-N的互作对产量、pH与NO3--N的互作对含糖率的影响均达显著水平。模拟寻优结果表明,介质环境pH在6.5～7.5范围内,适当调节NO3--N和NH4+-N比例,可获得较高的甜菜块根产糖量,总N为16.0mmol.L-1、NO3--N:NH4+-N为16∶0时及N为19.2mmol.L-1、NO3--N∶NH4+-N为5∶1时产糖量最佳。

Hydroponics experiment based on Hoagland solution was conducted to establish the regression models of root yield and sugar content respond to muhiple - factor compound treatment in sugar beet （ Beta vulgaris L. ） variety Tianyan 7 and analyze the individual and interactive effects of the factors by using the quadratic rotation regression design of three factors and five levels, taking pH, nitrate （ NO3- -N） and ammonium （NH4＋ -N） as test factors. Results showed that the individual effect of test factors on the root yield and sugar content of sugar beet decreased in the order of NO3- -N 〉 pH 〉 NH4＋-N; positive effect on root yield and sugar content was found under pH within 6.2 - 7.0, on the contrary, negative within pH 7.0 to 7.8. Root yield was influenced positively by NO3- -N （0 -16mmol· L^ - 1 ）, and sugar content was afftected negatively. The factor of NH4＋ -N （0 - 8.0mmol· L^ - 1 ） had positive effect on root yield, 8.0 - 16mmol· L^ - 1 of NH4＋ -N had negative effect on root yield. Sugar content was influenced negatively by NH4＋-N （0 - 16mmol· L^ - 1 ）. There was no significant interaction between the factors, except NO3--N and NH4＋ -N to RY and pH and NO3- -N to RSC.Simulated optimization test showed that, under the could be gained by adjusting ratio of NO3- -N and N NH4＋ -N was 16：0 with the total N was 16mmol· L^ - 1 total nutrient conditions at pH 6.5 to 7.5, the higher sugar yield H4 -N properly in the environmental media, especially, when NO3 N/ and NO3- N/NH4＋-N was 5：1 with N of 19.2mmol· L^ - 1 .